Objective.-To evaluate the treatment of bacterial vaginosis with metronidazole to determine if there is a therapeutic regimen that is superior to all others with regard to cure and recurrence rates. Data Sources.-Computer-assisted literature search, Medical Subject Index review, and references cited in articles identified. Study Selection.-Clinical trials comparing different oral metronidazole regimens in which diagnostic criteria for bacterial vaginosis and criteria to detect cure to treatment were described. Date Extraction.-Articles that met inclusion criteria were critically appraised and those that passed were included in the analysis. Of 52 initial articles, 10 met criteria for inclusion and passed critical appraisal. Data Synthesis.-Patients were divided in groups according to the duration of therapy received: group A (n=413), 2-g single dose; group B (n=193), 2-g single daily dose for 2 days; group C (n=317), 5 days; and group D (n=280), 7 days. Cure rates on initial evaluation for the groups were 85%, 87%, 86%, and 87%, respectively. Chi-2 contingency table analysis showed no significant difference in cure rates among the groups (P=.78). Only 465 of these patients were evaluated for recurrence of disease. There was no significant difference in cure rates after 4 weeks of therapy (P=.4). Conclusions.-A 2-g single-dose metronidazole regimen is as effective as a single daily dose given for 2 days or a 5-day course or a 7-day course.